Evolutionary development study describes a critical fold that sends the reptile off on its own
Turtles may be weird, but according to new research, they’re not that weird. Their funny arrangement of shell and shoulder is just the same old land-dweller vertebrate stuff — with a little fold.
At first a turtle embryo grows much like a chicken or mouse. But then the developing body wall makes a critical fold, and the usual body plan starts to become an unusual turtle, Hiroshi Nagashima of Kobe Univers